The present invention relates generally to a stirrup insert for use in equestrian riding. More particularly, the present invention relates to a stirrup insert that is rigidly attached to an equestrian riding stirrup to improve the traction of the stirrup and better retain the rider's foot under demanding riding conditions. 
Typical equestrian riding gear includes a saddle with stirrups attached to straps extending from the saddle for receiving the feet of a rider. Clearly, the stirrups are an integral part of the riding equipment used by most equestrian riders. In general, riders use stirrups to retain or secure their feet thereby allowing them to maintain their balance while riding and while performing various riding maneuvers. Moreover, riders use stirrups to maintain proper posture and maneuverability while negotiating obstacles and clearing jumps. To further maintain the proper relationship between the rider's mounted position and the horse, the weight of the rider seated upon the saddled horse is distributed in a balanced manner through the saddle and the stirrups.  
When the horse is in forward motion, the rider's feet in the stirrups act as a natural suspension system through flexion of the ankle joints. The rider places the ball of his foot on the base of the stirrup and by the controlled flexion of the ankle joint, the rider can create a natural suspension system. This type of riding is most prevalent in English riding, and especially in jumping. Sufficient suspension of the rider is necessary to maintain proper balance for performance purposes as well as safety. In addition, proper suspension must be maintained to avoid unnecessary adverse contact of the rider on the horse's back thereby avoiding injury to the horse. In jumping, the problem is compounded by increased dynamic forces generated directly and the point where the rider's foot is in contact with the stirrups. The amount of downward pressure on the stirrups is dependent upon the rider's weight, forward momentum, position, the amount of contact in the seat of the saddle and the height of the jump. With greatly changing dynamic at this critical contact point, it is clear that the rider's foot must maintain positive contact with the stirrup. Should contact be lost, the riser cannot maintain the proper balance and suspension required to remain on the horse, as a result the rider's foot may slip out of the stirrup in the middle of a jumping maneuver with disastrous consequences. 
In competitive show jumping, for example, a rider navigates around a course containing several jumps, usually more than a dozen, which are set at prescribed heights depending upon the qualifications of the rider. Therefore, in this environment a rider would encounter both normal riding conditions and jumping conditions in rapid and alternating succession resulting in frequent and substantial variations in the dynamic forces between the rider's foot and the stirrup.  
In conventional stirrups, the side bars and the footplate are an integral piece or the footplate is attached to the side bars such that the footplate is rigidly attached to the ends of the side bars. The stirrups hang down from the saddle generally in a vertical plane, perpendicular to the ground, with the footplate being generally parallel to the ground. The foot plate generally includes a central opening to receive an insert to enhance the frictional interface between the bottom of the rider's boot and the surface of the stirrup. The standard prior art insert is a rubber insert that has a ribbed top surface and two rubber hooks extending from the bottom surface thereof to engage the foot plate adjacent the opening. While this configuration is well suited to the forces exerted during casual riding, these inserts are easily dislodged during more strenuous riding maneuvers, particularly jumping. 
Another prior art attempt at providing a suitable insert includes the provision of a rubber pad with bendable metal arms attached thereto. The arms are designed to be bent around the foot plate of the stirrup to hold the pad in place. These pads however are easily torn from the metal arms under the dynamic stresses encountered in jumping. Further, because the fastening means provides a small degree of latitude in lateral motion, the arms are subjected to a high degree of dynamic stress causing them to bend or break. 
There is therefore a need for a novel stirrup insert that is rigidly attached to the foot plate of a stirrup while providing an enhanced traction surface to retain the rider's foot. There is a further need for a durable stirrup insert that maintains its functionality under the dynamic loading typically associated with equestrian jumping.  